Ulysses S. Grant and Robert E. Lee are forever linked by history as the great military rivals of the Civil War. Yet less than two decades earlier they had been comrades—both West Point graduates, both wearing U.S. blue, and both fighting in the same cadre in the Mexican War. William T. Sherman, Jefferson Davis, Stonewall Jackson, and nearly all of the Civil War's greatest leaders had been forged in the heat of Vera Cruz and Monterrey in the 1840s. Full of dramatic battles, daring rescues, and secret missions, Martin Dugard's dramatic account of the Mexican War tells how a group of young men came together to fight as friends, only to fight as enemies a few years later.

"Canny in its depictions of intriguing, powerful personalities and Machiavellian politics, meticulous in its textured battlefield and logistical descriptions, The Training Ground has the fast-paced feel of a good historical novel, but it's all well-researched fact."—American History